So I started reading Harry Potter & the Deathly Whoosits last night, and I couldn't help but be struck by something.
So Ron's dad is talking about getting to fiddle with the motorcycle and he claims that maybe he can learn how brakes work. Please note that Ron's dad most likely spent a hunk of time fiddling with that flying car we saw earlier.
Now, this isn't my supposedly pointing out a continuity error, but instead pointing out what could be a pretty hard-hitting detail about the Wizarding world -- See, motorcycle brakes work pretty much like car brakes, which work like bicycle brakes, train brakes and even the brakes on 18th Century carriages and one-digit Century wagons. You've got the wheels that go round and round, and you've a thing that you push or pull which presses hunks of stuff against the wheel so it slows it down. Ever since the first person hooked a heavy cart up to an ox and realized that if that ox slows down from a fast trot, the wagon's momentum will make it slam into the back of the ox unless they find a way to slow it down, brakes have been about the same.
And yet, the Wizarding world apparently has no clue about them.
Mind, the only wheeled things I can think of that are used in the Wizarding world are wheelbarrows (no need for brakes there), the Thestral-drawn carriages (no wheels there, actually, but I thought I'd cite them anyway should someone bring them up), and the Hogwarts Express train, itself.
The last one is the oddity, but it might not work on mundane principles at all (I can't recall if it was ever shown to be a normal train or what amounts to a large stage-prop train, hauled along by magic).
Still! This almost leads me to believe that perhaps the Wizarding world never really caught onto the idea of hitching a large wheeled object to one or more large beats of burden?